Air pollution and climate change effects on plant ecosystems: from cell to ecosystem
Session 2. Urban green: sinks or sources of air pollution and climate change
Urban environments that are stressful for plant function and growth will become increasingly widespread in future. Cities have to cope with rising poor air quality (e.g. ozone, particulate matter and nitrogen dioxide) impacting human health, quality of life, citizens’ well-being and ecosystem services provided by urban forests. Analyzing plant responses to urban conditions represents an important opportunity to gain an insight into immediate physiological responses, tolerance of plants and extent and mechanisms of short- and long-term plant adaptations often simulating climate change conditions. Green infrastructure, such as trees, shrubs and green roofs, can improve air quality by removing air pollutants but the same time can enhance air pollution by increased emissions of biogenic volatile organic compounds. Municipalities and city planners need a quantitative and concrete assessment of the role of urban vegetation in affecting air quality at city scale as well as guidelines for tree planting and maintenance strategy to maximize air quality and minimize disservices. Urban vegetation, as a cost-effective and nature-based approach, aids in meeting clean air standards and should be taken into account by policymakers. The session, organized in the framework of the AIRFRESH project (LIFE19 ENV/FR/00086), includes presentations focusing on the effects of the main urban pollutants on plants as well as estimations of the mitigation potential by urban plants in urban and peri-urban environment.
Session 3. Plant ecosystems in a changing world: monitoring, modeling and risk assessment
New approaches (e.g. field experiments, Earth-Observation, epidemiological studies) and sophisticated modeling are under development to study plant ecosystems in a changing world. Based on observations, modeling approaches are emerging to develop coupled biogeochemical-ecological models, to predict the combined effects of climate change, air pollution, atmospheric deposition and other stressors on plant ecosystems functioning and diversity. The objective of this session is to discuss different approaches to bridge the knowledge gaps in different scientific domains (air pollution, atmospheric deposition, climate change, impacts in terms of growth, health, yield, distribution and biodiversity loss) in order to: i) translate observations and predictions into future scenarios, including socio-economic implications; ii) improve understanding of interaction and feedbacks between climate change, air pollutants and effects upon plant ecosystems; iii) quantify the ecosystems responses to air pollution and changing climate conditions; and iv) provide risk maps for plant ecosystems at regional and local scale.
Session 4. Atmospheric deposition: consequences for plant ecosystems
Atmospheric deposition, particularly of nitrogen (N) and sulfur (S), continues to impact aquatic and terrestrial ecosystems across the globe. In South Asia, East Asia, Southeast Asia and Japan, N and S deposition remain at high levels. In China, N and S deposition levels are the highest reported in the world, and studies of the ecological effects on atmospheric deposition are relatively recent with much yet to be discovered regarding plant ecosystem responses. Nutrient limitations, and the effect of N deposition on carbon sequestration, are now recognized as important process information to include in global carbon models. More research is needed to incorporate climate change and air pollution as interactive factors in developing critical loads models for plant ecosystems under conditions of multiple biotic and other environmental stressors. The session focuses on how atmospheric nitrogen and sulfur deposition is impacting on plant ecosystems and how they function, to integrate research findings so that solid management strategies can be developed for better environmental policies and adaptation of plant ecosystems that ensure sustainability.
Session 5. Crops and trees: productivity and ecological processes
The objective of this session is to highlight the effects of multiple stressors (e.g. pest outbreaks, fires, air pollution, climate change) on plant ecosystems and ecosystem services (including food security), whether biogenic or anthropogenic, abiotic or biotic, at the intersection of different trophic levels, and at the stand to landscape level. The yields quantity and quality of crops and productivity of trees will be discussed along with ecological processes in crop and tree systems, including interactions between plant-plant, plant-herbivore and plant-insects as well as associations with symbiotic organisms such as mycorrhizae in trees and N-fixing organisms in crops. The session also addresses the confounding effects of air pollutants on insect receptors and pollination. The main aim is to evaluate strategies for maximizing yield, productivity and other environmental services of crops and trees under multiple stressors.
Session 6. Genetic, biochemical and physiological mechanisms underlying stress responses of plant ecosystems
In aiming to explore the current state of knowledge on climate change and air pollution stress on plant ecosystems, and to identify priorities and challenges of future research towards consolidating plant ecosystems health, productivity, sustainability and ecosystem services worldwide, it is important to understand linkages between genetic responses and resulting physiological activities, i.e. genetic control of physiological responses. This session focuses on discussing physiological, biochemical and genetic mechanisms, and their inter-linkages, underlying plants’ responses to climate change and air pollution. As well, genetic variation in acclimation and adaptive phenological, physiological and anatomical traits is addressed.
Session 7. Forest protection against ozone: new approaches towards an effective policy decision-making
In the framework of the National Emission Ceilings Directive, Member States have to ensure the monitoring of negative impacts of ground-level O3 upon ecosystems based on a network of monitoring sites to allow the effectiveness assessment of the Directive in Environmental protection. Unique in the world, the project MOTTLES (LIFE15 ENV/IT/000183) takes place in the main European areas at highest and medium risk of O3 injury, relative to human well-being and vegetation impacts, i.e. Southern and central Europe and combines field epidemiology with plant-responses to O3. New monitoring approaches and epidemiological investigations (e.g radial growth, crown defoliation and visible foliar O3 injury) are under development to provide useful information for establishing the best standards and thresholds for forest protection from O3. All these developments, with focus on the most modern techniques, are discussed in this session.
The session contributes to i) develop a better understanding of ozone impacts on forest; ii) evaluate many different metrics for forests protection, with a focus on stomatal O3 flux; iii) provide best practices for sustainable forest management; and iv) guide management decisions and efficient policy recommendations toward increased health, sustainability and productivity forest resilience worldwide.